The 644 Patent covers the use of prasugrel (Eli Lilly’s EFFIENT) in combination with aspirin in diseases caused by thrombus or embolus. Prasugrel and aspirin were previously known to have inhibitory activity against platelet aggregation. The 644 Patent claims the novel combination of prasugrel and aspirin. Apotex made the following attacks on validity:

Patentable subject matter. Apotex argued that the 644 Patent was invalid, as it claims a “mere aggregate and not a patentable combination”, and was therefore not an invention under section 2 of the Patent Act. Based on expert evidence, Justice Manson found that the 644 Patent discloses that the claimed combination results in an effect on platelet aggregation that is new, useful and more than the sum of the effects of each agent alone and therefore rejected this ground of invalidity.

Obviousness. Justice Manson found the claims were obvious. The inventive concept was found to be the combination of prasugrel and aspirin that has a greater effect than the sum of the effects of each drug alone. Prasugrel belonged to a class of molecules called thienopyridines, two of which (ticlopidine and clopidogrel) had been successfully combined with aspirin for an antithrombotic effect. Justice Manson found there was motivation to find the solution of the 644 Patent, as inhibiting two known platelet activation pathways using a thienopyridine and aspirin together was known to result in improved therapies. Substituting one thienopyridine for another in combination with aspirin had also been successful. Therefore, although the exact effects of combining prasugrel with aspirin could not be predicted with certainty, a skilled person could reasonably expect the combination to achieve the same synergistic, therapeutic effect as clopidogrel (and possibly ticlopidine) and aspirin. Testing was done relatively quickly and, although technical, was based on well-known methods. Therefore, it was self-evident and obvious to try the combination of prasugrel and aspirin.

Sufficiency and overbreadth. Apotex argued that the specification of the 644 Patent did not instruct the skilled person how to administer prasugrel and aspirin sequentially, since the time period between administrations would have to be determined experimentally, and that the 644 Patent claimed more than was invented. However, the expert evidence indicated that a skilled person would be able to determine the time period using the 644 Patent and common general knowledge. Therefore, Justice Manson found that the patent was not invalid for lack of disclosure or overbreadth.

Conclusion

The preceding is intended as a timely update on Canadian intellectual property and technology law. The content is informational only and does not constitute legal or professional advice. To obtain such advice, please communicate with our offices directly.